The Primary Breast Cancer Therapy Group (NSABP) is a multidisciplinary cooperative group consisting of surgeons, radiation therapists, pathologists, medical oncologists and, at present, is conducting three major protocols. This institution has been a participant in this Project since May 1, 1971. This grant application is being submitted for support for our institution's participation in the protocols conducted by the Primary Breast Cancer Therapy Group (NSABP) and should be considered with the Headquarters grant application submitted by the Project Chairman, Dr. Bernard Fisher. In addition to participating in Protocol 4, we have provided the Headquarters Office with samples of breast tumor for estrogen binding. We will collect blood samples for hormonal assay to determine the effect of chemotherapy on ovarian activity and for determination of biological markers. A new protocol to evaluate segmental mastectomy is in the final planning stage and should be implemented within the next few months for patients with Stages I and II breast cancer. Extensive information has been obtained relative to the pathology specimens submitted by us from patients in Protocol No. 4.